With such a steering, it is possible to steer a vehicle in two different manners, either via the steering unit or via the steering valve. In many cases the vehicle can also be steered using both steering unit and steering valve at the same time. A steering unit is here understood to be a hydro-mechanical steering unit, which can be activated by a steering handwheel or a similar arrangement. Such a steering unit has a directional section and a measuring motor section, so that the measuring motor connected to the working connection arrangement can be supplied with a certain amount of hydraulic fluid having the right direction. The steering valve, however, is activated either directly or indirectly via a joy-stick or another arrangement. It merely controls the throughput of hydraulic fluid to the steering motor, without being reset by a measuring motor section.
To ensure that the steering motor can be controlled by both the steering unit and the steering valve, they both have to be connected to the supply connection arrangement. Accordingly, both arrangements are permanently exposed to the pressure of the hydraulic fluid supplied by the supply connection the pressure of the hydraulic fluid supplied by the supply connection arrangement. This causes a substantial load.